The present disclosures relate to semiconductor chip packaging, and more particularly, to a semiconductor chip package featuring crack arrest features and method of forming the crack arrest features.
In the process of manufacturing a package containing an embedded device for build-up package technology, dielectric brittleness and cracking occur due to thermal cycling, in particular, when using epoxy based photo defined dielectric or other similar low elongation organic dielectric materials. An embedded device build-up panel comprises one or more semiconductor die and an encapsulant. The encapsulant surrounds the one or more semiconductor die on at least three side surfaces of each semiconductor die, with at least an active side surface of the one or more semiconductor die exposed for further processing. In addition, the encapsulant generally comprises an epoxy based material, which has a glass transition temperature (Tg) of less than 180° C. Accordingly, low temperature processing would be advantageous for making the embedded device build-up panel. However, low temperature processing limits the selection of a build-up dielectric material.
Build-up dielectric materials can include traditional polyimide and Benzocylobutene (BCB) which are very tough and not susceptible to cracking. However, traditional polyimide and BCB materials need to be cured at a high temperature, greater than 200° C., (T_cure>200° C.). Accordingly, use of traditional polyimide and BCB materials for build-up dielectric material on an embedded device build-up panel is undesirable, due to the temperature processing constraint of the panel.
One temperature compatible dielectric material comprises, for example, a photo-imageable dielectric. In particular, the cure temperature for the photo-imageable dielectric is on the order of one hundred fifty degrees Celsius (T_cure=150° C.). However, the temperature compatible dielectric material has been found to be prone to fatigue cracking in regions above the die during reliability testing, which included temperature cycling.
Accordingly, there is a need for an improved method and apparatus for overcoming the problems in the art as discussed above. In particular, it would be desirable to provide a method and apparatus to confine a dielectric crack within a small area and suppress its growth in an embedded device build-up package.
The use of the same reference symbols in different drawings indicates similar or identical items. Skilled artisans will also appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve the understanding of the embodiments of the present invention.